Variable capacity gear pump



July 2'7, 1954 Filed Dec. 5, 1949 A. P. HELDENBRAND VARIABLE CAPACITY GEAR PUMP 2 Sheets-Sheet l FIG. 3

INVENTOR.

A. P HELDENBRAND FIG.4

July 27, 1954 A. P. HELDENBRAND .2,684,636

VARIABLE CAPACITY GEAR PUMP 2 Shee'cs--SheeI 2 Filed Dec. 5, 1949 o: 7W wr -O INVENTOR. N AJ? HELDx-:NBRAND Patented July 27, 1954 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to pumps and, more particularly, but not by way of limitation, to rotary gear pumps.

An important object of this invention is to provide a rotary pump having a variable capacity capable of being minutely controlled from full capacity to zero capacity.

Another object of this invention is to provide a rotary vpump which is eflicient, durable, simple in construction and may be economically manufactured.

Another object of this invention is to provide a variable capacity rotary pump for use in pumping liquids and which may be used as a hydraulic transmission in trucks, tractors, automobiles, rotary draw works and the like.

Other objects and advantages of the invention will be evident from the following detailed description, read in conjunction with the accompanying drawings, which illustrate my invention.

In the drawings:

Figure 1 is a longitudinal sectional view partially in elevation for clarity.

Figure 2 is a transverse sectional view taken on line A-A of Figure 1 partially in elevation for clarity.

Figure 3 is a transverse sectional View taken on line B--B of Figure l with the housing removed.

Figure 4 is an elevational view of the right end of Figure l with the housing removed.

Figure 5 is a longitudinal sectional view partially in elevation of a modification of the pump shown in Figure l.

Figure 6 is a transverse sectional view taken on line C-C of Figure 5 partially in elevation for clarity.

Referring to the drawings in detail, reference character 2 designates a rotary pump having an outer housing 4 and end plates 6 and 8 secured thereto by a plurality of bolts I Il.

In the lower portion of the housing 4 are two apertured cylindrical blocks I2 and I4 arranged in spaced relation on the opposite sides of an impeller member I6. The impeller I6 is rigidly mounted on a drive shaft I8 extending through the block I2 and impeller I5, and partially through block I4, and is connected at one end to a suitable prime mover (not shown) for actuating vthe pump. Also mounted on the shaft I8 is a pinion gear adjacent the outer end of block I2. The blocks I2 and I4 are provided with internal bushings 22 and 24 through which shaft I8 passes. A plurality of ball bearing sets 26 are mounted in circular recesses 28 in the opposite ends of block I2 and in the inner end of block I4 to provide a bearing support for shaft i8. The upper surface of block I2 is concave in conguration and is provided with a longitudinal key seat 30 (Fig. 3) therein, and the upper surface of block I4 is convex in shape and is provided with a transverse groove 32 therein near one end for .purposes as will be hereinafter set forth. Suitable packing 34 is provided in a recessed flange in end plate 6 around shaft I8 and is secured therein by a packing nut 36 held by a plurality of bolts 33.

The upper portion of the housing 4 is provided with two apertured cylindrical blocks 42 and 44, arranged in spaced relation on the opposite sides of an impell'er wheel 4S rigidly mounted on a sleeve 48. Block 42 is provided with a longitudinal key or projection on the lower surface thereof adapted to move in key seat 30 of block I2. A transverse groove 52 on the outer periphery thereof, terminates on the opposite sides of the key 50 and is adapted to receive a split sealing ring 54. The block 42 is provided with a recessed portion 55 in the outer end thereof for receiving a ball bearing race 58. The block 44 is provided with a tapered bore 68 having a ball bearing race disposed therein. A control shaft 62 extends through end plate 8 and a suitable stufng gland 64 to a suitable source of manual or mechanical power (not shown) for controlling the longitudinal movement of upper blocks 42 and 44 and mpeller 46. A concave lower surface 66 in block 44 cooperates with an upper convex surface of block I4 to permit longitudinal movement between the blocks. The concave surface 66 also permits block 44 to move over gear I6. The outer periphery of block 44 is in continuous contact with a sealing ring 68 retained in a transverse groove lil in the inner periphery of housing 4 and groove 32 in block I4. The sleeve 48 receives a washer I2 and nuts 'I4 on the end thereof disposed in bore Si! of block. 44 for retaining blocks 42 and 44 and impeller 4S in a proper relation. A male spline I (Fig. 2) is provided on the inner periphery of sleeve 48 and is adapted to move in a longitudinal key seat 'I8 provided in the outer eriphery of an auxiliary shaft 80. Although only one spline is shown, it is to be understood that a plurality of splines may be utilized if desired. The shaft is provided at one end with a pinion gear 82 mounted above, and in working engagement with the gear 28 on lower shaft I8. Shaft 80 is also provided with a longitudinal bore 84 extending from the end thereof adjacent end plate 8 to a transverse aperture 85 located in proximity with the inner face of gear 82 for a purpose hereinafter set forth. A reduced end portion 88 of the shaft receives a Washer Si! and nut 92. The end portion 88 is supported by ball bearing 913 retained in a recessed flange 95 of end plate 6 by a cover 98 and plurality of bolts illu.

rihe end plates and ii are provided with apertures |62 and |04 respectively for receiving a conduit it. The housing l is provided with an inlet aperture iBS (Fig. 2) substantially media arranged longitudinally in housing d (not shown) and adapted to be connected to a source of liquid supply (not shown). An outlet aperture HB is provided opposite the inlet iii-ii, and receives a conduit (not shown) to the desired point of delivery. n conduit l i2 interconnects with conduit lfd. The pump 2 is provided with suitable supports iid.

Figures 5 and 6 illustrate a modification of the pump provided with a hydraulic control system having a four-way valve i i5 which may be adapt- Operation ln operation the drive shaft iE is rotated in a counter-clockwise direction (referring to Fig. 2) by any suitable prime mover (not shown), thereby rotating gear and impeller iS in a counterolockwise direction and gear 22, shaft Sii, and impeller in an opposite clockwise direction.

Assuming the variabl posed as shown Fig. l, as long a constant supply of liquid is present at inlet tot, liquid will be forced by the radial teeth or lobes 23 and i3@ on the impellers i5 and fit, respectively, about the inner periphery of housing i and displaced through outlet The communication established by conduits iii@ and H2 and between outlet l if: and the opposite ends of housing l permits the discharge pressure of the supply liquid to be transmitted to the outer end faces i32 and 53E- of blocks i2 and fit, respectively, thereby maintaining a liquid seal 1ietween the end surfaces of impeller 4t, and the outer faces of blocks d2 and Lid.

The capacity or the pump may be diminished by reducing the contact surface between impellers iii and 4t. This is accomplished by moving control shaft E2, and hence blocks 42 and d4, and impeller 3E to the left (referring to Fig. l). it Will ce apparent that the capacity may be varied as desired by simply moving control shaft e2 longitudinally to the left or right and that the relative lengths of the blocks and impellcrs may be selected to permit the pump to operate at zero capacity.

As the blocks liz? and and impeller it move to the left from the position shown in Fig. 1, the liquid contained in housing i adjacent end face E32 of block Q2 is transferred by conduit iiil to the end ld of blo .i i4 in housing l; and as blocks i2 and ill and impeller d6 move to the right, liquid contained in housing i adjacent end face i3d. of block lil is transferred to the left end |32 of block 5:2 in housing 4. This transfer of liquid from one end of housing l to the other is assisted by bore 84 and aperture Sii in shaft 3@ in the preferred embodiment (Fig. l)

e aperture in the auxiliary shaft Sii are capacity gear 135 is dis- L Figures 5 and 6 disclose a modification of the control means and includes a four-way valve I5 having three operating positions. When the valve ||5 is in the rst position (not shown) a portion of the liquid being pumped fioWs through outlet conduit |28, the four-way valve |5, and conduit |24 to the end |34 of block 44, thereby forcing blocks it and 42 and impeller 46 to the left (referring to Figure 5). Simultaneously liquid Contained in the housing 4 to the left of block 42 is discharged through conduit |22, four-way valve H5, and `conduit H8 to combine with the liquid being pumped. With the valve in a second position (not shown) a portion of the liquid being pumped flows through conduit |20, four-way valve lill and conduit |22 to the outer end |32 of block 32, thereby forcing blocks 42 and 44 and impeller d6 to the right. Simultaneously liquid contained in the housing 4 to the right end |34 of block ifi is discharged through conduit |24, four-way valve H5 and conduit H3 to combine with the liquid being pumped. When the valve is in a third position, all communication between conduits H8, lili?, 522 and |24 is prevented, therefore, blocks 42 and it and impeller 46 are prevented from moving to the left or right by a static huid lock.

It is readily seen that when it is desired to reduce the capacity of the pump, the four-way valve is set in the first position mentioned above; and to increase the capaicty of the pump, the four-way valve is set in the second position above mentioned and to maintain the desired constant capacity of the pump, the four-way valve is set in the third position.

From the foregoing it would be apparent that the present invention contemplates a variable capacity gear pump; wherein the upper impeller i6 and its cooperating blocks 42 and i4 are capable of being independently moved longitudinally relative to the stationary blocks l2 and i4 and the rotating lower impeller iB. Movement of impeller 4e relative to impeller l will insure a variance in displacement of the fluid discharging around the inner periphery of housing 4. Furthermore, the concave-convex relation between block i4 and 44 and the keyway 5G permits sliding movement between the upper blocks and the lower blocks. rI'he concave lower surface permits block i4 to slide over the teeth |23 of impeller i6. The longitudinal movement of impeller :it may be accomplished either manually or automatically by any suitable type of prime mover, or may be accomplished hydraulically, as is shown in the modification. it will be understood that the invention is not limited to the control means disclosed herein, but may utilize other suitable types if desired.

Changes may be made in the combination and arrangement of parts as heretofore set forth in the specification and shown in the drawings, it being understood that any modification in the precise embodiment of the invention may be made Within the scope of the following claims without departing from the spirit of the invention.

I claim:

l. In a rotary pump, a housing, inlet and outlet apertures in said housing, a rotatable drive shaft extending into said housing, an auxiliary shaft in spaced relation to said drive shaft, an impeller on said drive shaft, a second impeller on said auxiliary shaft in engagement with said `first mentioned impeller, said second impeller being longitudinally movable on said auxiliary shaft, stationary bloolr nsf-oi Y Le 'i drive shaft on the oppo les oi mentioned impeller, longitudinally movable bloeit mans mounted on said aua. opposite sides of said second one said niovaI le blocs; ineens lr' a in sliding cont let with the block means providing clearanee for the irst mentioned impeller upon movement of said mov" able block means, the other or" said movable blo-sli means being slidingy keyed to the other staw ti iary block means in a direction parallel to tne auxiliary shaft, seals around movable bloei; means providing a seal at each end of the inipeller, valve means, conduit means providing communication between said valve means and the inlet and outlet apertures the outer ends of said movable blok means, said valve means being operative to alte ser; provide pump discharge pressure on either outer. end of said movable block means and simultanea ously provide pump inlet pressure to the opposite outer end of said movable block means for moving said second impeller and movable bloc means longitudinally in variable distances and in either direction.

2.` In a rotary pump, Comprising a housing, in let and outlet fluid apertures provided in said housing, a rotatable drive shaft extending into said housing, an auxiliary shaft arranged in vertical spaced relation to said drive shaft, an inipeller on said drive shaft, a second impeller on said auxiliary drive shaft in engagement with said first mentioned impeller, said second impeller being longitudinally movable on the auxiliary shaft relative to the rst impeller, stationary block means provided on opposite sides of the first impeller, longitudinally movable block means provided on opposite sides or the second impeller, one of said movable block means having a lower concave side in sliding contact with the adjacent stationary block means providing clearance for the rst mentioned impeller upon movement of said movable block means, the other of said movable block means being slidingly keyed to the other stationary block means in a direction parallel to the auxiliary shaft, seals eaeli le block means providing a seal at each end oi the second impeller, valve means, conduit inea-ns providing communication between said valve means and the inlet and outapertures and the opposite outer ends oi said movable block means, said valve means being operative in one position to provide pump discharge pressure on one outer end of said movable block means to inove said second impeller and movable block means in one direction for decreasing the displacement capacity of the pump,

i valve means ope'ative in another posinon to provide pump discharge pressure at an opposite end oi the movable block means from of the first mentioned end to move said second impeller and movable bloes: means lonftudinally in a direction opposite to the rst .mentioned direction and provide an increase i the displacement capacity o the pump.

iieierenees in the nie of this patent UNTED STATES PATENTS Number Name Date '311,662 Herdman Oct. 2l, 1902 '288,648 Riegel May 2, 1905 1,621,726 Johnson Mar. 26, 1912 1,099,238 Day June 9, 1914 1,742,215 Pigott Jan. 7, 1930 2,652,419 Moore et al Aug. 25, 1936 2,149,326 l-Vilkin Mar. 7, 1939 42,157,285 Egersdorfer May 9, 1939 2,293,126 Fersing Aug. 18, 1942 2,332,701 Egorsdorfer Aug. 14, 1945 2,484,789 l'rlill et al. Oct. 11, 1949 2,496,115 Clarke Dec. 6. 1949 FOREIGN PATENTS Number Country Date 409,998 Germany Feb. 16, 1925 565,963 Germany Oct. 6, 1938 OTHER REFERENCES Ser. No. 429,040, Egersdorfer (A. P. 0.), published Mal 11A 1943. 

